In circuit-switched (CS) mobile telecommunications systems, a mobile station (MS) sends a signal or message, which is picked up by a base transmitting station (BTS) and then routed by a base station controller (BSC). The signal or message is forwarded by the BSC to an associated mobile switching center (MSC), for routing to the appropriate destination, for example, a public switched telephone network, PSTN, or other telecommunications node or network.
To increase multimedia and Internet capabilities, and for other reasons, most mobile telecommunications systems are being migrated from use of a circuit-switched core network to use of a packet-switched (PS) protocol network. Systems using a PS network nevertheless typically needs support for handling calls routed through non-PS systems (for example, PSTN). Ideally, support for existing mobile stations (MS's), for example, call initiation, call termination, in a PS signaling network environment will operate in a manner transparent to the user. Furthermore, ideally, such support should also permit supporting new features and capabilities. However, end users are often stymied by a lack of standardization to enable such migration from circuit-switched networks to packet-switched mobile networks to continue.
Therefore, what is needed is a method for call clearing between a circuit switched network and a PS network for communicating with a mobile station.